Also known as SMT, surface mount technology places electronic components and fixes directly onto the circuit boards. Advances in technology have meant that SMT now allows for smaller board level components and consequently, smaller end products. Think of the size difference in early mobile phones and today's tiny cell phones, for example. Surface mount components can be soldered using two basic techniques - using a soldering iron or using an oven. Though the process is fairly easy, it requires care and a stable hand specially when using a soldering iron. The process starts with applying a thin layer of solder paste, which is a sticky mixture of tiny solder particles and flux, to the SMT pads which are present on the PCB and are used to hold the SMT components. Then the component is placed on the pads and carefully aligned. Next, using a clean solder iron or the oven, the component needs to be tacked into place properly by soldering two opposite pins. Once in place, the alignment is rechecked and the soldering completed. The SMT method of mounting has a number of main advantages over older methods, allowing as it does for the placement of components in exact positions on both sides of a circuit board, reducing costs and reducing size at the same time. Though cost reductions have only come over time, the initially cost of creating the machines and designs needed to undertake surface mounting are higher than the old through-hole based mounting. Many people still suggest that the older methods of mounting components are easier to repair, but as SMT has developed enough, along with advances in the repair tools, the methods and costs of repairing surface mount boards has fallen. While it is still possible to undertake manual soldering repairs, there have been professional rework systems designed as well which have improved the method and cost of repairs. Surface mount components now range into three main categories, Passive SMDs (including resistors and capacitors), Transistors and Integrated Circuits. There are currently still some electronic components that require the old drilled through and lead wire methods, but the numbers are on a dramatic decline. Look for further advances in surface mount technology in the coming years. As the technology improves, the electronic components will get smaller and smaller. Learning how to use them now will keep you on top of the industry. PCB (printed circuit board) technology has come a long way since they were first invented in the 1930's! The construction of electrical circuits via through-hole technology was largely the norm until IBM began to seriously improve the practicality of surface-mount PCBs. Today's surface-mount technology allows for the mass production of electronics and has greatly reduced the cost to the consumer. Here are some of the other advantages of surface-mount technology for PCBs. -- Surface-mount allows for much smaller components to be used which, in turn, allows for smaller, more portable and lightweight electronic device applications. -- Because the components can be so much smaller, the complexity of the PCB can be increased over the same or a smaller surface area. There can be many more components and many more connections as well than there could ever be using through-hole techniques. -- The soldering process involved with surface-mount can be done on a large scale via automation. This expedites production and reduces the need for man-power. -- Placement of components is much more reliable than it would be if it were done via through-hole or even if humans soldered by hand. The reason for this is that the natural surface tension created when the soldering sheet becomes molten in the oven naturally pulls the components into their exact proper positions. -- Surface-mount PCBs are much stronger and resistant to external stress than their through-hole counterparts. When an electronic device is dropped or shaken, if the components have been surface-mounted the electrical connection is much more likely to remain intact. Most PCBs today are manufacturer using surface-mount technologies. Although the processes may vary, the concept remains the same: surface-mount is still the best thing going. SMD Bestückung